I went ahead and pre-ordered as well, since it is physical. Never played any "Mana" games, but the gameplay looks fun.
Well, if you're interested in getting your feet wet with the series...
I think Secret of Mana has aged well, so I definitely recommend that.
Sword of Mana is a remake of the first Mana game/Final Fantasy Adventure. It gets a lot of flack, but I think it's an enjoyable little game.
Secret of Mana 2 is usually regarded as the best. It's a great game and has the highest replay ability. Another one that I highly recommend.
I'd avoid Dawn of Mana and Heroes of Mana. Neither of them are fun; both for their own reasons.
Children of Mana is the Mana game I recommend when you run out of other games in the series to play.
Legend of Mana is another fun one, but it doesn't feel like it's a part of the Mana universe.